1. Technical Field
The present invention relates generally to an optical system, and more particularly to a compact optical image capturing system for an electronic device.
2. Description of Related Art
In recent years, with the rise of portable electronic devices having camera functionalities, there is an increasing demand for an optical image capturing system. The image sensing device of ordinary photographing camera is commonly selected from charge coupled device (CCD) or complementary metal-oxide semiconductor sensor (CMOS Sensor). In addition, as advanced semiconductor manufacturing technology enables the minimization of pixel size of the image sensing device, the development of the optical image capturing system towards the field of high pixels. Therefore, the requirement for high imaging quality is rapidly rising.
The conventional optical system of the portable electronic device usually has a two-piece lens. However, to take pictures in a dark environment, the optical system needs a large aperture. An optical system with large aperture typically has several problems, such as, large aberration, poor image quality at periphery of the image, and is burdensome to manufacture. In addition, a wide-angle optical system usually has large distortion. Therefore, conventional optical system do not provide high optical performance in these environments.
There is a need to increase the quantity of light entering the lens and the angle of field of the lens. In addition, the modern lens also needs improved properties, including high pixels, high image quality, a small size, and high optical performance.